Reading device

ABSTRACT

A reader device ( 1 ) includes a mounting surface ( 5 ) on which a passport ( 7 ) with a page to be read ( 9 ) is placed, a light source ( 21, 31 ) for illuminating the page to be read ( 9 ), and a camera ( 13 ) for picking up an image of the page to be read ( 9 ). The light source ( 21, 31 ) is arranged outside a front area of the page to be read. The page to be read ( 9 ) contains a near-edge code positioned close to an edge of the page to be read ( 9 ). The light source ( 21, 31 ) includes an infrared LED array ( 23 ) and a white LED array ( 33 ). An infrared LED ( 25   e ) and a white LED ( 35   f ) included in the infrared LED array ( 23 ) and the white LED array ( 33 ), respectively, and located at a near-edge code position corresponding to the near-edge code are arranged closer to the page to be read than the other infrared LEDs ( 25   a  to  25   d ) and white LEDs ( 35   a  to  35   e ) in a direction perpendicular to the mounting surface ( 5 ). Thus, a reader device is provided which allows a good image to be obtained even if a relevant page of an object to be read is deformed.

TECHNICAL FIELD

The present invention relates to a reader device for picking up an imageof an object to be read and carry out reading processing on the image,and in particular, to arrangement of light sources for image pickup.

BACKGROUND ART

Reader devices are conventionally known which read codes such ascharacters from various objects to be read. The object to be read is,for example, a document with a plurality of sheets bound up. Thedocument is, for example, a passport.

The conventional reader device is configured to illuminate a surface tobe read of an object to be read with infrared light to pick up an imageof a code on the surface to be read, thus acquiring an infrared lightimage. The infrared light image is subjected to reading processing suchas OCR (Optical Character Recognize) to allow the code to be recognized.The use of infrared light as illumination light allows prints in blackink, which is likely to absorb infrared light, to be emphasized to makea background image relatively unclear. This makes the code in a sharpercontrast with the remaining part of the image. Furthermore, a fraud canbe detected by comparison with an image picked up by visible light andshowing characters or graphics drawn with ink that absorbs infraredlight and reflects visible light.

Furthermore, when an image of an object to be read is displayed on amonitor or the like, for example, to allow an operator to visually checkthe image, the object to be read is illuminated with visible lightinstead of infrared light to acquire a visible light image.Alternatively, like infrared light images, the visible light image maybe subjected to OCR to allow the code to be recognized.

For example, Patent Literature 1 discloses a reader device configured toirradiate an object to be read with both infrared light and visiblelight. This conventional device uses visible light to generate ahologram image, while using infrared light to read a code printed in alayer under the hologram.

Furthermore, the reader device needs to avoid image pickup under aspecular reflection condition. The specular reflection condition is suchthat the direction of image pickup coincides with the incident angle ofillumination light, that is, the direction of specular reflection. Whenan image of a surface to be read is picked up under the specularreflection, reflected light is excessively intense and what is called“washed-out highlight” occurs. This may prevent the good image frombeing obtained. The “washed-out highlight” refers to white-out thatoccurs in a part of an image as a result of the saturated dynamic rangeof an imaging device. In this phenomenon, the visible light image whitesout to prevent a subject from showing up in the image or to make thesubject in the image difficult to see. In the conventional art, in orderto avoid the specular reflection condition, the surface to be read isilluminated from the side and picked up from the front. This enables thereflection angle of illumination light (=incident angle) to be increasedto avoid the specular reflection condition (see, for example, PatentLiterature 2).

However, the conventional reader device poses the following problems inconnection with deformation of the object to be read.

An object to be read such as a passport may wet with an owner's sweat,for example, when carried in the owner's pocket. The wetting and thesubsequent drying or the like subjects the edge of the object to be readto wave-like deformation (corrugation). When such wave-like deformationoccurs, imaging of the edge may be carried out under the specularreflection condition, resulting in washed-out highlight. If a code suchas characters is present at the edge, the code may fail to appearclearly in the image. Thus, desirably, illumination is properly providedso as to suitably prevent the wave-like deformation of the edge to allowan image of the code at the edge to be picked up.

For example, passports are covered with a laminate or the like. Hence,washed-out highlight is likely to occur in an image of the passportunder the specular reflection condition. Furthermore, in many of thepassports, a code is printed so as to end in a corner of thecorresponding page. The above-described wave-like deformation of thepage is likely to be significant in the corner of the page. Thus, whenan image of a passport subjected to wave-like deformation is picked upunder illumination with visible light, a part of the code located in thecorner may be difficult to see as a result of washed-out highlight. Inparticular, one or two characters in the corner are difficult to see.Thus, desirably, illumination is properly provided so as to preventpossible washed-out highlight in the part of the code located at theedge.

To avoid the above-described problem, the device may include a cover forholding the object to be read. However, when the object to be read is apassport or the like, a reading operation needs to be performed quickly.Thus, desirably, illumination can be properly provided without the useof a cover or the like, even if the object to be read slightly floats.

Furthermore, for miniaturization of the device, an optical path throughwhich images are read may be bent using a mirror, to reduce the volumeof the whole device. In this case, the mirror is arranged between thesurface to be read and a camera. Reflected light from the surface to beread is bent by the mirror before reaching the camera. However, when themirror is provided, illumination light is also reflected by the mirrorand impinges on the surface to be read of the object to be read. As aresult, illumination unevenness may occur to degrade the reading abilityor make a display image difficult to see.

CITATION LIST Patent Literature

Patent Literature 1: Japanese Patent Laid-Open No. 6-247084

Patent Literature 2: Japanese Patent Laid-Open No. 2008-304860

SUMMARY OF INVENTION Technical Problem

The present invention has been developed against the above-describedbackground. An object of the present invention is to provide a readerdevice capable of providing the good image even if a relevant page ofthe object to be read is deformed. Another object of the presentinvention is to provide a reader device capable of reducing illuminationunevenness resulting from provision of a mirror.

Solution to Problem

An aspect of the present invention is a reader device comprising anobject placing unit on which an object to be read with a surface to beread is placed, a light source for illuminating the surface to be readplaced on the object placing unit, and an imaging unit for picking up animage of the surface to be read illuminated by the light source, whereinthe light source is arranged outside a front area of the surface to beread, and the surface to be read includes a near-edge code positionedclose to an edge, and wherein the light source includes a light emittingelement array comprising a plurality of light emitting elements, and alight emitting element included in the light emitting element array andlocated at a near-edge code position corresponding to the near-edge codeis arranged closer to the surface to be read than the other lightemitting elements in the light emitting element array in a directionperpendicular to the object placing unit.

As described below, the present invention includes other aspects. Thus,the disclosure of the present invention is intended to provide some ofthe aspects of the present invention and not to limit the scope of thepresent invention described and claimed herein.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-unital view of a reader device according to a firstembodiment of the present invention.

FIG. 2 is a cross-unital view of the reader device according to thefirst embodiment of the present invention, showing the arrangement oflight sources.

FIG. 3 is a cross-unital view of the reader device according to thefirst embodiment of the present invention, showing the arrangement ofthe light sources.

FIG. 4 is a perspective view of the reader device according to the firstembodiment of the present invention.

FIG. 5 is a diagram showing the interior of the reader device with anupper case of the device removed.

FIG. 6 is a diagram showing a page to be read of a passport that is anobject to be read.

FIG. 7 is a diagram illustrating the principle of the present inventionfor prevention of possible washed-out highlight at the position of acode when a passport is subjected to wave-like deformation.

FIG. 8 is a cross-unital view of a reader device according to a secondembodiment of the present invention.

FIG. 9 is a cross-unital view of the reader device according to thesecond embodiment of the present invention, showing the arrangement oflight sources.

FIG. 10 is a cross-unital view of the reader device according to thesecond embodiment of the present invention, showing the arrangement ofthe light sources.

FIG. 11 is a perspective view of the reader device according to thesecond embodiment of the present invention.

FIG. 12 is a diagram showing a page to be read of a passport that is anobject to be read.

FIG. 13 is a diagram illustrating the principle of the present inventionfor prevention of possible washed-out highlight at the position of acode when a passport is subjected to wave-like deformation.

DESCRIPTION OF EMBODIMENTS

The present invention will be described below in detail. However, thedetailed description below and the accompanying drawings are notintended to limit the present invention. Instead, the scope of thepresent invention is limited by the accompanying claims.

First Embodiment

The reader device according to the present invention includes an objectplacing unit on which an object to be read with a surface to be read isplaced, a light source for illuminating the surface to be read placed onthe object placing unit, and an imaging unit for picking up an image ofthe surface to be read illuminated by the light source. The light sourceis arranged outside a front area of the surface to be read, and thesurface to be read includes a near-edge code positioned close to anedge. The light source includes a light emitting element arraycomprising a plurality of light emitting elements, and a light emittingelement included in the light emitting element array and located at anear-edge code position corresponding to the near-edge code is arrangedcloser to the surface to be read than the other light emitting elementsin the light emitting element array in a direction perpendicular to theobject placing unit.

In this configuration, the light source is arranged locally closer tothe object to be read in a place where the code is present close to thesurface to be read. Thus, even if the edge of the surface to be read issubjected to wave-like deformation as a result of wetting of the objectto be read, the part of the code located close to the edge is preventedfrom being imaged under a specular reflection condition. Hence,illumination can be properly provided so as to prevent the part of thecode located at the edge from being difficult to see as a result ofwashed-out highlight.

Furthermore, the reader device according to the present invention mayfurther include a mirror for redirecting an optical path between thesurface to be read and the imaging unit. The light emitting elementarray may be positioned such that main light from the light emittingelements is prevented from traveling to the surface to be read afterreflection by the mirror.

This configuration can eliminate illumination unevenness resulting fromreflection by the mirror to obtain a good image. Thus, the configurationcan improve a character recognition rate and the accuracy with which theimage is checked. The configuration also facilitates visual recognitionof the image acquired.

Furthermore, in the reader device according to the present invention,the near-edge code is provided at an end of the edge of the surface tobe read. The light emitting element located at the near-edge codeposition is positioned at an end of the light emitting element array.

In this configuration, the code is positioned at the end of the edge ofthe surface to be read, that is, in a corner of the surface to be read.The corner is more seriously affected by deformation. However, in thepresent invention, the light source is locally located closer to thesurface to be read, thus properly preventing possible washed-outhighlight in the corner.

Furthermore, the reader device according to the present invention may beconfigured as follows. The reader device includes a mirror forredirecting an optical path between the surface to be read and theimaging unit. The mirror is inclined to the surface to be read. Thelight emitting element located at the near-edge code position ispositioned at one of opposite ends of the light emitting element arraywhich is closer to the mirror.

This configuration enables a reduction in illumination unevennessresulting from provision of the mirror. The configuration focuses on theillumination unevenness occurring at the near-edge code and can reducethe illumination unevenness for the following two reasons. The mirror isinclined and the near-edge code is thus located close to the mirror.According to the present invention, the light emitting element locatedclose to the near-edge code may be arranged away from the mirror(assuming that all the light emitting elements are arranged in a line,the light emitting element located close to the near-edge code isarranged very close to the mirror, but the position of this lightemitting element is further from the mirror than this assumed position).This enables a reduction in the illumination unevenness occurring in thenear-edge code portion as a result of the adverse effect of the mirror.Furthermore, the illumination unevenness associated with the mirror issuch that the surface to be read appears brighter at a position furtherfrom the light emitting element and relatively dark at a position closerto the light emitting element. In contrast, in the present invention,the light emitting element is located close to the surface to be read.Hence, a place close to the light emitting element can be made brighter,enabling a reduction in illumination unevenness. Thus, theabove-described two effects work synergistically to reduce theillumination unevenness occurring at the near-edge code. Therefore, thepresent configuration suitably exerts effects such as improvement of thereading ability.

Furthermore, in the reader device according to the present invention,the light source may include a first light source for irradiating thesurface to be read with first illumination light in a first wavelengthband and a first radiation angle in order to acquire a first image usedfor reading processing, and a second light source for irradiating thesurface to be read with second illumination light in a second wavelengthband wider than the first wavelength band and a second radiation anglewider than the first radiation angle in order to acquire a second imageused for an application including display.

This configuration serves to provide a reader device that uses theplural types of light sources to utilize the characteristics of thelight sources to allow the surface to be read to be suitably read. Theradiation angle corresponds to a range within which the illuminationlight exhibits a brightness of a predetermined level or higher, forexample, the range within which when a frontward brightness is set to bea reference value, the illumination light exhibits a brightnessaccounting for at least a predetermined rate of the reference value.

Furthermore, in the reader device according to the present invention,the first light source is an infrared light source, and the second lightsource is a visible light source. In this configuration, the infraredlight source is used to obtain an image for reading processing. Thevisible light source is used to obtain an image for display. The visiblelight source provides a wider wavelength band and a wider radiationangle than the infrared light source. Even with such plural types oflight sources, the advantages of the present invention are suitablyobtained.

Furthermore, in the reader device according to the present invention,the object to be read is a passport. In this configuration, even if theobject to be read is a passport covered with a laminate or the like,illumination can be properly achieved. The good image is obtained evenif the object to be read floats.

In the present invention, the light source is locally arranged closer tothe near-edge code as described above. Thus, the good image is obtainedeven if a relevant page of the object to be read is deformed.Additionally, in the present invention, the light source is properlyarranged as described above to enable a reduction in the illuminationunevenness resulting from the provision of the mirror.

A reader device according to an embodiment of the present invention willbe described with reference to the drawings.

In the present embodiment, the object to be read is a document or acard. In particular, an example of the document is a passport, and anexample of the card is a boarding card for an airplane. Furthermore, thepresent embodiment uses two light sources. A first light source is aninfrared light source. A second light source is a visible light source,particularly a white light source.

The reading device according to the embodiment of the present inventionis shown in FIG. 1 to FIG. 4. FIG. 1 to FIG. 3 are cross-unital views,and FIG. 4 is a perspective view. Furthermore, in FIG. 5, a top cover ofthe device has been removed, and light sources 21 and 31, a mirror 11,and a camera 13 are shown. FIG. 3 is a cross-unital view takenorthogonally to a cross unit AA shown in FIG. 2. FIG. 3 shows thedifference in height between both an infrared LED 25 e and a visiblelight LED 35 f shown in FIG. 1 and the other LEDs in an LED array. Thevisible light LED is also referred to as the white LED.

First, as shown in FIG. 4, a reader device 1 includes a substantiallycubic housing 3 with a mounting surface 5 provided on the top thereof.The mounting surface 5 is a transparent glass plate. The mountingsurface 5 is where a passport 7 that is an object to be read is placedfor reading and corresponds to an object placing unit according to thepresent invention. Furthermore, the housing 3 includes stop units 41 and43 that are perpendicular to each other. The stop units 41 and 43include stop walls. Two perpendicular sides of the passport 7 arebrought into abutting contact with the stop units 41 and 43 to positionthe passport 7 on the mounting surface 5.

FIG. 6 schematically shows the passport 7. The passport 7 is a kind ofdocument as described above and is formed of a plurality of sheets boundup at the center thereof. The passport 7 includes a page to be read 9with a long edge 53 parallel to a binding edge 51 and a short edge 55perpendicular to the binding edge 51. The long edge 53 and the shortedge 55 correspond to a long side and a short side, respectively, of thepage to be read 9, which is rectangular. The page to be read 9 containsa photograph 57 and a code 59. The code 59 is a string of characters orthe like to be read by the reader device 1. In the passport 7, the code59 is provided along the long edge 53. The passport 7 is placed on themounting surface 5 so that the page to be read 9 faces downward.

FIG. 1 is a cross-unital view showing the reader device 1 cut along lineA-A in FIG. 4. FIG. 2 is a diagram showing the arrangement of the lightsources as viewed from the same direction as that in FIG. 1. FIG. 3 is adiagram showing the arrangement of the light sources as viewed from thedirection of an arrow B in FIG. 2.

As shown in FIG. 1, a mirror 11 is provided under the mounting surface5. The camera 13 is provided beside the mirror 11. The camera 13corresponds to an imaging unit according to the present invention. Thecamera 13 utilizes reflection by the mirror 11 to pick up an image ofthe passport 7 from below. The camera 13 may pick up both an infraredlight image and a visible light image. Alternatively, the infrared lightimage and the visible light image may be picked up by separate cameras.In this case, the imaging unit is formed of a plurality of cameras.

Furthermore, as shown in FIG. 1 to FIG. 3, the reader device 1 includesan infrared light source 21 and a white light source 31 both provided ina housing 3. The infrared light source 21 is formed of an infrared LEDarray 23 including a plurality of infrared LEDs 25 a to 25 e.Additionally, the white light source 31 is formed of a white LED array33 including a plurality of white LEDs 35 a to 35 f. The infrared LEDarray 23 and the white LED array 33 are parallel to the mounting surface5 (page to be read 9). The infrared LEDs 25 a to 25 e and the white LEDs35 a to 35 f are attached to a circuit board 45. In addition, theinfrared LED 25 e and the white LED 35 f are arranged close to themounting surface 5.

As shown in FIG. 2, the infrared light source 21 (infrared LED array 23)and the white light source 31 (white LED array 33) are arranged outsidea front area of the page to be read 9 and outside both short edges 55.

Furthermore, as shown in FIG. 1 to FIG. 3, the infrared light source 21(infrared LED array 23) and the white light source 31 (white LED array33) are arranged away from the page to be read 9 in the perpendiculardirection. Here, the perpendicular direction is perpendicular to thepage to be read 9 placed on the mounting surface 5, that is,perpendicular to the mounting surface 5. In the present embodiment, theinfrared light source 21 and the white light source 31 are arranged at afirst distance D1 from the page to be read 9 in the perpendiculardirection. However, the white LED 35 f and the infrared LED 25 e locatedclose to the corner of the object to be read are arranged at a seconddistance D2 at which the white LED 35 f and the infrared LED 25 e liecloser to the mounting surface than the other LEDs. One of the white LED35 f and the infrared LED 25 e may be exclusively arranged at theposition corresponding to the second distance D2 depending on the objectto be read, without departing from the scope of the present invention.Additionally, in the example illustrated in FIG. 1 and other figures,the white LEDs and the infrared LEDs are arranged at the first distanceD1 in a line. However, either the white LEDs or the infrared LEDs may bearranged at a distance longer than the first distance D1. Alternatively,some of the LEDs may be arranged at a distance longer than the firstdistance D1 regardless of whether the white LEDs or the infrared LEDs.Thus, it is also preferable that the light emitting element arrays bearranged so as to be slightly displaced from each other in theperpendicular direction, allowing the object to be read to be evenlyilluminated with light.

As described above, the white LED 35 f, included in the white LED array33 and located at an end of the array 33 which is furthest from thebinding edge 51, is exceptionally arranged closer to the page to be read9 than the other white LEDs 35 a to 35 e in the perpendicular direction.The white LED 35 f, located at the furthest end, is arranged adjacent tothe infrared LED 25 e, located at the furthest end of the infrared LEDarray 23. As described above, if the object to be read is read usinginfrared light, the infrared LED 25 e may be exclusively arranged closerto the page to be read 9. If the visible light image may be focused on,the white LED 35 f may be exclusively arranged closer to the page to beread 9.

Now, the operation of the reader device 1 according to the presentembodiment will be described. First, a user mounts the passport 7 on themounting surface 5 so that the page to be read 9 faces downward. Thelong edge 53 and short edge 55 of the passport 7 are brought intoabutting contact with the stop units 41 and 43 to position the passport7. Then, an image of the page to be read 9 is picked up in response tothe user's operation.

When the device carries out reading processing, the infrared lightsource 21 illuminates the page to be read 9 with infrared light, and thecamera 13 generates an infrared light image. The infrared light image isused for the reading process and corresponds to the first imageaccording to the present invention. Then, a reading processing unit (notshown in the drawings) processes the infrared light image to recognizethe code such as characters. In the infrared light image, a backgroundimage is prevented from showing up clearly, whereas the code such ascharacters to be recognized is in a sharp contrast with the backgroundimage. Thus, the reading process can be accurately carried out. Thereading processing unit may be formed of a computer. Alternatively, thereading processing unit may be provided outside the reader device 1.

Furthermore, when an image for display is to be acquired, the whitelight source 31 irradiates the page to be read 9 with white light, andthe camera 13 generates a visible light image. The visible light imageis output to a monitor (not shown in the drawings), on which the visiblelight image is displayed. The visible light image corresponds to thesecond image according to the present embodiment.

Now, the arrangement of the infrared light source 21 and the white lightsource 31 according to the present embodiment will be described infurther detail. The positions and directions of the infrared lightsource 21 and the white light source 31 are basically set so as to avoidthe specular reflection condition. The specular reflection conditionrefers to the coincidence of the direction of image pickup with thedirection of specular reflection of illumination light. When an image ofthe page to be read 9 is picked up under the specular reflectioncondition, reflected light obtained is excessively intense, leading towhat is called washed-out highlight. This prevents the good image frombeing obtained. Also for the infrared light source 21, the specularreflection condition needs to be avoided in order to ensure the readingability. In the present embodiment, the infrared light source 21 and thewhite light source 31 are arranged outside the front area of the page tobe read 9 and illuminate the page to be read 9 from the side. Thisallows an incident angle to be set wider and serves to avoid thespecular reflection condition and thus washed-out highlight.

In the present embodiment, the arrangement of the light sources is settaking into account not only the above-described factors but alsopossible deformation of the passport 7 and the adverse effect of themirror 11. The factors concerning the deformation as well as thearrangement of the light sources will be described below.

“Setting the Arrangement of the Light Sources with Deformation of theObject to be Read taken into Account”

First, the arrangement of the light sources with deformation of thepassport 7, which is the object to be read, taken into account will bedescribed. Here, focus is placed on the arrangement of the white LED 35f, located at the end of the white light source 31, and the infrared LED25 e, located at the end of the infrared light source 21. Mainly thearrangement of the white LED 35 f will be described below. Thearrangement of the infrared LED 25 e is set similarly to that of thewhite LED 35 f for generally similar reasons.

As shown in FIG. 7, the arrangement of the white LED 35 f relates to theposition of the code 59 on the page to be read 9. The code 59 isprovided close to and along the long edge 53 of the page to be read 9.The end of the code 59 reaches the vicinity of the short edge 55 of thepage to be read 9 and is positioned in the corner of the page to be read9.

The white LED 35 f is positioned at the further end of the white LEDarray 33. The position of the white LED 35 f corresponds to the code 59in the direction of the array. The white LED 35 f is arranged higherthan the other white LEDs 35 a to 35 e in the white LED array 33, thatis, closer to the page to be read 9 in the perpendicular direction.

The passport 7 may be held in an owner's pocket for a long time and wetwith the owner's sweat. The wetting and the subsequent drying or thelike or putting and taking the passport 7 into and out of the pocketsubjects the edges of the passport 7 to wave-like deformation(corrugation), with the end of each edge subjected to curleddeformation. In the pocket, the short edge 55 is positioned at thebottom portion of the pocket. Thus, the short edge 55 is likely toundergo such deformation.

When the wave-like deformation occurs, the angle between the page to beread 9 and the white light source 31 increases and decreasesperiodically along the short edge 55. In a place where the angle betweenthe page to be read 9 and the white light source 31 is wider, theincident angle (=output angle) is narrower, thus allowing the specularreflection condition to be locally established. Consequently, when thewave-like deformation occurs, the specular reflection condition isperiodically established along the short edge 55. As a result, as shownin the left half of FIG. 7, a plurality of small washed-out areas arecreated at intervals along the short edge 55. Depending on the shape ofthe corrugation, any of the washed-out areas overlaps the code 59, theend of which lies in the washed-out area, as shown in FIG. 7. Thus, inan image generated using the white light source 31, the end of the code59 is difficult to see. In particular, about one or two characterslocated at the end of the code 59 are difficult to see.

The code 59 is a target for automatic reading using the infrared lightsource 21. However, even in a visible light image picked up using thewhite light source 31, the entire code 59 needs to be displayed, forexample, to allow the result of reading to be checked. Thus, such awashed-out highlight phenomenon as described above needs to beprevented.

To accomplish this object, the present embodiment is configured suchthat the white LED 35 f, positioned so as to correspond to the code 59,is locally arranged close to the page to be read 9. Thus, the incidentangle (=output angle) of white light is wider at the position of thecode 59 than in the other places. Hence, even with a change in the angleof the corner of the page to be read 9 resulting from deformation, theincident angle is prevented from decreasing excessively. The specularreflection condition can thus be avoided. This serves to preventpossible washed-out highlight at the position corresponding to the code59 as shown in the right half of FIG. 7.

When the white LED 35 f is arranged close to the page to be read 9, theirradiation range of the white LED 35 f is narrowed. This may causeilluminance unevenness. However, in the present embodiment, only thewhite LED 35 f is locally arranged at the different position. The otherLEDs illuminate the entire page to be read 9 with light over a wideradiation angle. Hence, possible illuminance unevenness is notsignificant enough to affect the check of the image.

Furthermore, as shown in FIG. 7, washed-out areas remain in a placewhere the code 59 is not provided. However, in the areas other than theone in which the code 59 is written, information with a high level ofimportance (for example, a photograph of the owner's face) is locatedclose to the center of the page so as to avoid the contamination ordeformation of the page. Thus, the present embodiment acquires a goodimage of the area of the code 59, which is likely to be deformed, whilesomewhat permitting the occurrence of washed-out highlight in areas inwhich information with a high level of importance is unlikely to bewritten.

Conventional copiers and the like include a cover for holding an objectto be read. Such a cover may be included in the reader device in orderto prevent the adverse effect of deformation of the passport 7. However,the reading of the passport 7 is carried out, for example, for animmigration check at an airport and thus needs to be quickly finished.Thus, if each passport 7 is set and held using the cover, the operationrequires a long time. In contrast, as shown in FIG. 1, the reader device1 according to the present embodiment need not include a presser coverand allows the passport 7 to be set on the mounting surface 5 in a shorttime.

The arrangement of the white LED 35 f has been described. As describedabove, the infrared LED 25 e is arranged closer to the page to be read 9than the other infrared LEDs 25 a to 25 d for similar reasons. Thus, thespecular reflection condition involved in the deformation of thepassport 7 can be avoided. Furthermore, the adverse effect of theillumination unevenness is sufficiently insignificant.

“Determination of Arrangement of the Light Sources with Reflection bythe Mirror taken into Account”

Now, setting of the arrangement of the light sources with reflection bythe mirror 11 taken into account will be described. Illumination lightis not only emitted directly to the page to be read 9 but also reflectedby the mirror 11 to impinge on the page to be read 9. The illuminationlight from the mirror 11 overlaps the direct illumination light. Suchillumination light from the mirror 11 may cause illumination unevenness.

When such illumination unevenness occurs, the page to be read 9 becomespartly brighter under the effect of the illumination light from themirror 11. If the mirror 11 is inclined as shown in FIG. 1, the distancebetween the mirror 11 and the light emitting elements (LEDs) variesgradually. A reduction in the distance between the mirror 11 and thelight emitting elements increases the range on the page to be read 9covered by the illumination light from the mirror 11. Thus, as shown inFIG. 1, when the mirror 11 is inclined, the illumination unevenness isshaped like an isosceles triangle with the long edge 53 of the passport9 as a base.

In the present embodiment, the light emitting elements (LEDs) arepositioned such that the main illumination light from the light emittingelements (LED) is reflected by the mirror 11 and prevented fromtraveling to the page to be read 9. Specifically, the light emittingelements are arranged as far from the mirror 11 as possible. Thisenables a reduction in the adverse effect of the mirror 11 and thus theillumination unevenness.

In the present invention, the main illumination light has a sufficientintensity to meet the requirement for the ability to read images. Forinfrared light, the main illumination light has a sufficient intensityto allow automatic recognition to be carried out sufficientlyaccurately. For visible light, the main illumination light is brightenough to allow the user to read an image on a display. When a visiblelight image is automatically recognized, the main illumination light isbright enough to allow a recognition process to be carried outsufficiently accurately.

More specifically, the main illumination light is centered around thefrontward direction of the light emitting elements and spans an angularrange that meets the requirement for the reading ability. The angularrange of the main illumination light may be the same as theabove-described range of radiation angle of the light emitting elements.

In the present embodiment, the light emitting elements are positionedsuch that the main illumination light is prevented from traveling to thepage to be read 9 after the reflection by the mirror 11. That is, thelight emitting elements are arranged as far from the mirror 11 aspossible in the perpendicular direction or closer to the page to be read9. This allows the light emitting elements to be positioned such thatthe irradiation light reflected by the mirror 11 fails to reach the pageto be read 9.

Moreover, as described above, when the mirror 11 is inclined, the rangeof the illumination unevenness increases with decreasing distancebetween the mirror 11 and the light emitting elements. Thus, theillumination unevenness forms an isosceles triangle with the long edge53 of the passport 9 as a base. Hence, even at positions where themirror 11 is located closer to the light emitting elements, the lightemitting elements are preferably arranged so as not to be excessivelyclose to the mirror 11.

As described above, the present embodiment enables a reduction inillumination unevenness and an increase in character recognition rateand the accuracy with which the image is checked but also facilitatesvisual recognition of the image acquired.

“Setting of Arrangement of the Light Sources with Reflection by theMirror taken into Account (the Arrangement of the White LED 35 f and theInfrared LED 25 e)”

As already described, in the present embodiment, the white LED 35 f andthe infrared LED 25 e are arranged closer to the page to be read 9 thanthe other LEDs. This arrangement is suitably set taking into account notonly the above-described deformation of the passport 7 but also theadverse effect of reflection of the illumination light from the mirror11. The arrangement of the white LED 35 f will be described below butthe following description also applies to the infrared LED 25 e.

Here, the illumination unevenness occurring at the code 59, that is, anear-edge code is focused on. Since the mirror 11 is inclined, the code59 is positioned close to the mirror 11. As already described, the rangeaffected by the reflection by the mirror 11 increases with decreasingdistance between the mirror 11 and the light emitting elements.According to the present embodiment, the white LED 35 f, located closeto the code 59, is arranged away from the mirror 11 (assuming that allthe white LEDs 35 a to 35 f are arranged in a line, the light emittingelement 35 f, located close to the near-edge code, is arranged veryclose to the mirror 11, but the position of the white LED 35 f isfurther from mirror 11 than this assumed position). This enables areduction in the illumination unevenness occurring at the code 59 as aresult of the adverse effect of the mirror 11.

Moreover, the present embodiment takes the following point into account.The illumination unevenness caused by the mirror 11 is such that thebrightness on the page to be read 9 increases consistently with thedistance from the light emitting elements. Thus, a place close to thelight emitting elements is relatively dark. In contrast, according tothe present embodiment, the white LED 35 f is arranged close to the pageto be read 9. Hence, the place close to the white LED 35 f can be madebrighter, enabling a reduction in illumination unevenness.

As described above, the arrangement of the white LED 35 f according tothe present embodiment exerts two effects. One of the two effects is areduction in the range of the illumination unevenness occurring in thecode 59 portion as a result of the arrangement of the white LED 35 faway from the mirror 11. The other effect is the possibility ofintensely illuminating the place close to the white LED 35 f (the placemade darker by the illumination unevenness) as a result of thearrangement of the white LED 35 f closer to the page to be read 9. Theseeffects work synergistically, and the present embodiment thus suitablyexerts effects such as improvement of the reading ability.

A modification of the present embodiment will be described. Theabove-described code 59 is an example of the near-edge code according tothe present invention. In the present invention, the near-edge code ispositioned close to the edge of the object to be read. Morespecifically, the near-edge code is positioned close to the lightsource-side edge to allow the image for display to be obtained. At leasta part of the code is positioned close to the light source-side edge. Ifthe object to be read is a passport, the near-edge code is positionedclose to the end of the edge (corner). Thus, the second light emittingelement, lying at the furthest end, is located closer to the surface tobe read (the second light emitting element emits the illumination lightfor display). However, the position of the near-edge code and the likevary depending on the type of the object to be read. The arrangement ofthe light sources may be correspondingly varied.

For example, the near-edge code may be positioned in the center of thelight source-side edge. In this case, the second light emitting elementcorresponding to the center of the light source-side edge is arrangedcloser to the object to be read in accordance with the position of thenear-edge code.

Furthermore, a plurality of light emitting elements may be arrangedcloser to the object to be read for one near-edge code. In other words,at least one light emitting element is arranged closer to the object tobe read without departing from the scope of the present invention. Thenumber of light emitting elements to be arranged closer to the surfaceto be read is suitably determined depending on the interval between theelements and the width of the code.

Additionally, the near-edge code need not be limited to a singleposition. A plurality of near-edge codes may be provided. In this case,a plurality of light emitting elements may be arranged at a plurality ofpositions each of which is closer to the object to be read.

In addition, the plurality of near-edge codes may have differentpurposes, meanings, applications, levels of importance, and the like.Thus, the arrangement of the light emitting element corresponding to therequired near-edge code may be exclusively changed.

As described above, various modifications may be made without departingfrom the scope of the present embodiment. However, the passport 7 isoften put in the owner's pocket during flight and is likely to undergowave-like deformation. Moreover, the passport 7 contains the code 59reaching the corner of the page to be read 9. Significant deformationand thus washed-out highlight are likely to occur in the corner.Therefore, the present embodiment is significantly advantageous to thepassport 7.

The reader device 1 according to the embodiment of the present inventionhas been described. In the present embodiment, the first light source isthe infrared light source 21. The first illumination light is infraredlight. The first wavelength band and the first radiation angle are thewavelength band and radiation angle of infrared light from the infraredlight source 21, respectively. Moreover, the first light emittingelement array and the first light emitting elements are the infrared LEDarray 23 and the infrared LEDs 25 a to 25 e, respectively. Furthermore,the second light source is the white light source 31, serving as anexample of a visible light source. The second illumination light is thewhite light. The second wavelength band and the second radiation angleare the wavelength band and radiation angle of white light from thewhite light source 31 are respectively. Moreover, the second lightemitting element array and the second light emitting elements are thewhite LED array 33 and the white LEDs 35 a to 35 f, respectively.Additionally, in the present embodiment, the object to be read is thepassport 7, the surface to be read is the page to be read 9, and theobject placing unit is the mounting surface 5.

According to the present embodiment, in a place where the code ispresent close to the edge of the surface to be read, the light source islocally arranged closer to the object to be read. Thus, even if the edgeof the surface to be read is subjected to wave-like deformation as aresult of wetting of the object to be read or the like, a part of thecode located close the edge can be prevented from being imaged under thespecular reflection condition. Therefore, illumination can be properlyprovided so as to prevent the part of the code located at the edge frombeing difficult to see as a result of washed-out highlight.

Furthermore, according to the present embodiment, the light emittingelement array is positioned such that the main light from the lightemitting elements is prevented from traveling to the surface to be readafter the reflection by the mirror. Thus, the present embodiment caneliminate the illumination unevenness resulting from the reflection bythe mirror to obtain the good image. Therefore, the present embodimentcan improve the character recognition rate and the accuracy with whichthe image is checked. The present embodiment also facilitates visualrecognition of the image acquired.

Furthermore, according to the present embodiment, the near-edge code isprovided at the end of the edge of the surface to be read. The lightemitting element located at the near-edge code position is positioned atthe end of the light emitting element array. In this configuration, thecode is positioned at the end of the edge of the surface to be read,that is, in the corner of the surface to be read. The corner is moreseriously affected by deformation. However, in the present invention,the light source is locally located closer to the surface to be read,thus properly preventing possible washed-out highlight in the corner.

Furthermore, according to the present embodiment, the reader deviceincludes the mirror for redirecting the optical path between the surfaceto be read and the imaging unit. The mirror is inclined to the surfaceto be read. The light emitting element located at the near-edge codeposition is positioned at one of opposite ends of the light emittingelement array which is closer to the mirror. This configuration enablesa reduction in the illumination unevenness occurring at the near-edgecode, and thus suitably exerts effects such as improvement of thereading ability.

Second Embodiment

If the object to be read is a passport or the like, then in many cases,the surface of the object to be read is covered with a transparentlaminate film. Moreover, an optical diffraction pattern may be providedon the front and back surfaces of the laminate film or inside thelaminate film in order to detect a fraud. Furthermore, in a documentsuch as a passport, the edge is likely to be curled or floats. Thus, thedocument is likely to float from the reader device. When such an objectto be read is illuminated, infrared light, which has a narrow wavelengthband, is unlikely to be affected, whereas visible light, which has awide wavelength band, may be affected. Specifically, if the visiblelight source is provided close to the surface to be read, an unintendedpattern such as a rainbow color may appear in the picked-up image underthe effect of the laminate and the diffraction pattern thereof. This maypreclude the good image from being obtained and make the image displayedon the monitor difficult to view.

To avoid the above-described problem, conventional copiers and the likeinclude a cover for holding the object to be read. However, when theobject to be read is a passport or the like, a reading operation needsto be performed quickly. Thus, desirably, illumination can be properlyprovided without the use of a cover or the like, even if the object tobe read slightly floats.

An object to be read such as a passport may wet with the owner's sweat,for example, while left in the owner's pocket. The wetting and thesubsequent drying or the like subjects the edge of the object to be readto wave-like deformation (corrugation). When such wave-like deformationoccurs, imaging of the edge may be carried out under the specularreflection condition, resulting in washed-out highlight. If a code suchas characters is present at the edge, the code may fail to appearclearly in the image. Thus, desirably, illumination is properly providedso as to suitably prevent the wave-like deformation of the edge to allowan image of the edge to be picked up.

For example, passports are covered with a laminate or the like. Hence,washed-out highlight is likely to occur in an image of the passportunder the specular reflection condition. Furthermore, in many of thepassports, a code is printed so as to end in a corner of thecorresponding page. The above-described wave-like deformation of thepage is likely to be significant in the corner of the page. Thus, whenan image of a passport subjected to wave-like deformation is picked upunder illumination with visible light, a part of the code located in thecorner may be difficult to see as a result of washed-out highlight. Inparticular, one or two characters in the corner are difficult to see.Thus, desirably, illumination is properly provided so as to preventpossible washed-out highlight in the part of the code located at theedge.

The background art of the present embodiment has been described usingthe infrared light source and the visible light source. However, theabove-described problems are not limited to the infrared light sourceand the visible light source; similar problems may occur if plural typesof light sources with different wavelength bands or radiation angles areused.

To solve such problems, the present embodiment provides a reader devicewhich can properly illuminate the object to be read even when pluraltypes of light sources with different wavelength bands or radiationangles are used and which provides the good image even if the object tobe read floats as a result of deformation of the corresponding page.

The reader device according to the present embodiment includes an objectplacing unit on which an object to be read with a surface to be read isplaced, a first light source for irradiating a surface to be read withfirst illumination light in a first wavelength band and a firstradiation angle in order to acquire a first image used for readingprocessing, a second light source for irradiating the surface to be readwith second illumination light in a second wavelength band wider thanthe first wavelength band and a second radiation angle wider than thefirst radiation angle in order to acquire a second image used for anapplication including display, and an imaging unit for picking up animage of the surface to be read illuminated by the first light sourceand the second light source. The first light source and the second lightsource are arranged outside the front area of the surface to be read.The second light source is located further from the surface to be readthan the first light source in the perpendicular direction.

In this configuration, the reader device includes the first light sourcefor the reading process and the second light source for display. Thefirst light source is, for example, an infrared light source. The secondlight source is, for example, a visible light source. According to thepresent embodiment, the first light source is arranged closer to thesurface to be read. Thus, even the first light source with the narrowerradiation angle can irradiate the required area on the surface to beread with light, ensuring the reading ability. Furthermore, the secondlight source is arranged further from the surface to be read than thefirst light source. This reduces the difference in the distance to thesecond light source which is dependent on the location of the surface tobe read. As a result, illumination unevenness is reduced, and the goodimage for display is obtained. Moreover, for example, it is assumed thatthe object to be read is covered with a laminate with an opticaldiffraction structure and that the object to be read floats from themounting surface. Even in this case, since the second light source isarranged relatively far from the surface to be read, the image fordisplay can be prevented from containing an unintended pattern and thedisplayed image can be prevented from being difficult to view. Thus, areader device can be provided which can properly illuminate the objectto be read even when plural types of light sources with differentwavelength bands or radiation angles are used and which provides thegood image even if the object to be read floats. Here, the wavelengthband refers to the band of wavelength of light. Monochromatic light hasa narrow wavelength band. White light has a wide wavelength band.

Furthermore, the reader device according to the present embodiment maybe configured as follows. The surface to be read includes a near-edgecode positioned close to an edge thereof. The second light sourceincludes a second light emitting element array including a plurality ofsecond light emitting elements. The second light emitting elementincluded in the second light emitting element array and located at anear-edge code position corresponding to the near-edge code is arrangedcloser to the surface to be read in the perpendicular direction than theother second light emitting elements in the second light emittingelement array.

In this configuration, in a place where the code is present close to theedge of the surface to be read, the second light source is locallyarranged closer to the object to be read. Thus, even if the edge of thesurface to be read is subjected to wave-like deformation as a result ofwetting of the object to be read or the like, a part of the code locatedclose the edge can be prevented from being imaged under the specularreflection condition. Therefore, illumination can be properly providedso as to prevent the part of the code located at the edge from beingdifficult to see as a result of washed-out highlight.

Furthermore, in the reader device according to the present embodiment,the first light source includes a first light emitting element arrayincluding a plurality of first light emitting elements. The second lightemitting element located at the near-edge code position may be arrangedadjacent to the plurality of first light emitting elements.

In this configuration, the second light source can be suitably locallyarranged closer to the surface to be read. Thus, an image can beacquired in which possible washed-out highlight at the edge is preventedto allow the code to appear properly.

The reader device according to the present embodiment may be configuredas follows. The near-edge code is provided at an end of the edge of thesurface to be read. The second light emitting element located at thenear-edge code position is positioned at the end of the second lightemitting element array.

In this configuration, the code is positioned at the end of the edge ofthe surface to be read, that is, in the corner of the surface to beread. The corner is more seriously affected by deformation. However,according to the present invention, the second light source is locallylocated closer to the surface to be read, thus properly preventingpossible washed-out highlight in the corner.

Furthermore, in the reader device according to the present embodiment,the first light source may be an infrared light source, and the secondlight source may be a visible light source. In this configuration, theinfrared light source is used to obtain an image for reading processing.The visible light source is used to obtain an image for display. Thevisible light source provides a wider wavelength band and a widerradiation angle than the infrared light source. Even with such pluraltypes of light sources, the object to be read can be properlyilluminated. Additionally, the good image is obtained even if the objectto be read floats.

Furthermore, in the reader device according to the present embodiment,the object to be read may be a passport. In this configuration, even ifthe object to be read is a passport covered with a laminate or the like,illumination with the first illumination light and the secondillumination light can be properly achieved. The good image is obtainedeven if the object to be read floats.

The reader device according to the embodiment will be described withreference to the drawings.

In the present embodiment, the object to be read is a document or acard. In particular, an example of the document is a passport, and anexample of the card is a boarding card for an airplane. Furthermore, afirst light source is an infrared light source. A second light source isa visible light source, particularly a white light source.

The reading device according to the present embodiment is shown in FIG.8 to FIG. 11. FIG. 8 to FIG. 10 are cross-unital views, and FIG. 11 is aperspective view.

First, as shown in FIG. 11, a reader device 101 includes a substantiallycubic housing 103 with a mounting surface 105 provided on the topthereof. The mounting surface 105 is a transparent glass plate. Themounting surface 105 is where a passport 107 that is an object to beread is placed for reading and corresponds to an object placing unitaccording to the present invention. Furthermore, the housing 103includes stop units 141 and 143 that are perpendicular to each other.The stop units 141 and 143 include stop walls. Two perpendicular sidesof the passport 107 are brought into abutting contact with the stopunits 141 and 143 to position the passport 107 on the mounting surface105.

FIG. 12 schematically shows the passport 107. The passport 107 is a kindof document as described above and is formed of a plurality of sheetsbound up at the center thereof. The passport 107 includes a page to beread 109 with a long edge 153 parallel to a binding edge 151 and a shortedge 155 perpendicular to the binding edge 151. The long edge 153 andthe short edge 155 correspond to a long side and a short side,respectively, of the page to be read 109, which is rectangular. The pageto be read 109 contains a photograph 157 and a code 159. The code 159 isa string of characters or the like to be read by the reader device 101.In the passport 107, the code 159 is provided along the long edge 153.The passport 107 is placed on the mounting surface 105 so that the pageto be read 109 faces downward.

FIG. 8 is a cross-unital view showing the reader device 101 cut alongline A-A in FIG. 11. FIG. 9 is a diagram showing the arrangement of thelight sources as viewed from the same direction as that in FIG. 8. FIG.10 is a diagram showing the arrangement of the light sources as viewedfrom the direction of an arrow B in FIG. 9.

As shown in FIG. 8, a mirror 111 is provided under the mounting surface105. A camera 113 is provided beside the mirror 111. The camera 113corresponds to an imaging unit according to the present invention. Thecamera 113 utilizes reflection by the mirror 111 to pick up an image ofthe passport 107 from below. The camera 113 may pick up both an infraredlight image and a visible light image. Alternatively, the infrared lightimage and the visible light image may be picked up by separate cameras.In this case, the imaging unit includes a plurality of cameras.

Furthermore, as shown in FIG. 8 to FIG. 10, the reader device 101includes an infrared light source 121 and a white light source 131 bothprovided in a housing 103. The infrared light source 121 is formed of aninfrared LED array 123 including a plurality of infrared LEDs 125 a to125 e. Additionally, the white light source 131 is formed of a white LEDarray 133 including a plurality of white LEDs 135 a to 135 f. Theinfrared LEDs 125 a to 125 e and the white LEDs 135 a to 135 f areattached to a circuit board 145.

As shown in FIG. 9, the infrared light source 121 (infrared LED array123) and the white light source 131 (white LED array 133) are arrangedoutside a front area of the page to be read 109 and outside both shortedges 155.

Furthermore, as shown in FIG. 8 to FIG. 10, the infrared light source121 (infrared LED array 123) and the white light source 131 (white LEDarray 133) are generally arranged away from the page to be read 109 inthe perpendicular direction. Here, the perpendicular direction isperpendicular to the page to be read 109 placed on the mounting surface105, that is, perpendicular to the mounting surface 105. In the presentembodiment, a second distance D2 from the page to be read 109 to thewhite light source 131 in the perpendicular direction is longer than afirst distance D1 from the page to be read 109 to the infrared lightsource 121 in the perpendicular direction (FIG. 10).

However, the white LED 135 f, included in the white LED array 133 andlocated at an end of the array 33 which is furthest from the bindingedge 151, is exceptionally arranged closer to the page to be read 109than the other white LEDs 135 a to 135 e in the perpendicular direction.Specifically, the white LED 135 f, located at the furthest end, isarranged adjacent to the infrared LED 125 e, located at the furthest endof the infrared LED array 123.

Now, the operation of the reader device 101 according to the presentembodiment will be described. First, the user mounts the passport 107 onthe mounting surface 105 so that the page to be read 109 faces downward.The long edge 153 and short edge 155 of the passport 107 are broughtinto abutting contact with the stop units 141 and 143 to position thepassport 107. Then, an image of the page to be read 109 is picked up inresponse to the user's operation.

When the device carries out reading processing, the infrared lightsource 121 illuminates the page to be read 109 with infrared light, andthe camera 113 generates an infrared light image. The infrared lightimage is used for the reading process and corresponds to the first imageaccording to the embodiment. Then, reading processing unit (not shown inthe drawings) processes the infrared light image to recognize the codesuch as characters. In the infrared light image, a background image isprevented from showing up clearly, whereas the code such as charactersto be recognized is in a sharp contrast with the background image. Thus,the reading process can be accurately carried out. The readingprocessing unit may be formed of a computer. Alternatively, the readingprocessing unit may be provided outside the reader device 101.

Furthermore, when an image for display is to be acquired, the whitelight source 131 irradiates the page to be read 109 with white light,and the camera 113 generates a visible light image. The visible lightimage is output to a monitor (not shown in the drawings), on which thevisible light image is displayed. The visible light image corresponds tothe second image according to the present embodiment.

Now, the arrangement of the infrared light source 121 and the whitelight source 131 according to the present embodiment will be describedin further detail.

First, setting of the first distance D1 from the page to be read 109 tothe infrared light source 121 will be described. The infrared lightsource 121 allows the code 159 shown in FIG. 12 to be read. The code 159is provided along the long edge 153 of the page to be read 109.

In contrast, the infrared LEDs 125 a to 125 e in the infrared lightsource 121 each have a narrow wavelength band and a narrow radiationangle. The radiation angle corresponds to a range within which theillumination light exhibits a brightness of a predetermined level orhigher, as described above. The radiation angle is defined as, forexample, the range within which when a frontward brightness is set to bea reference value, the illumination light exhibits a brightnessaccounting for at least a predetermined rate of the reference value. Thefirst distance D1 is long because of the narrow radiation angle. If theinfrared light source 121 is arranged away from the page to be read 109,an area located far from the infrared light source 121 can be irradiatedwith light, whereas an area located close to the infrared light source121 cannot be irradiated with light. This degrades the reading ability.Thus, the first distance D1 is set to a value such that the entire code159 including the area located close to the infrared light source 121can be irradiated with light, ensuring the reading ability.

Now, the arrangement of the white light source 131 will be described.The arrangement of the white light source 131 is set taking (1) to (3)described below into account.

(1) First, the position and direction of the white light source 131 areset to avoid the specular reflection condition. As already described,the specular reflection condition refers to the coincidence of thedirection of image pickup with the direction of specular reflection ofillumination light. When an image of the page to be read 109 is pickedup under the specular reflection condition, reflected light obtained isexcessively intense, leading to what is called washed-out highlight.This prevents the good image from being obtained. In the presentembodiment, the white light source 131 is arranged outside the frontarea of the page to be read 109 and illuminates the page to be read 109from the side. This allows an incident angle to be set wider and servesto avoid the specular reflection condition and thus washed-outhighlight.

(2) Furthermore, the brightness of white light varies significantlydepending on the distance from the white light source 131. When thesecond distance D2 from the page to be read 109 to the white lightsource 131 is short, the distance to the white light source 131 variesdepending on the position of the page to be read 109. This makes theillumination and thus the resultant image uneven. Specifically, acentral portion of the page to be read 109 is located away from thewhite light sources 131, arranged on the opposite sides of the page tobe read 109, and thus appears dark. Thus, the second distance D2 is setto a value at which the unevenness can be reduced to provide therequired image quality. As a result, the second distance D2 is setlonger than the first distance D1. Hence, the white light source 131 ispositioned further from the page to be read 109 than infrared lightsource 121.

(3) Furthermore, in many cases, the page to be read 109 of the passport107 is covered with a transparent laminate film. Moreover, in manycases, an optical diffraction pattern is provided on the front and backsurfaces of the laminate film or inside the laminate film in order todetect a fraud. Furthermore, in a document such as the passport 107, theedge is likely to be curled or float. Thus, the passport 107 has theproperty of being likely to float from the reader device 101.

When such a passport 107 is illuminated, illumination with infraredlight, which has a narrow wavelength band, is unlikely to be affected,whereas illumination with visible light, which has a wide wavelengthband, may be affected. Specifically, if the white light source 131 isprovided close to the page to be read 109, an unintended pattern such asa rainbow color may appear in the picked-up image under the effect ofthe laminate and the diffraction structure thereof. This may precludethe good image from being obtained and make the image displayed on themonitor difficult to view. Thus, in the present embodiment, the seconddistance D2 for the white light source 131 is set to a value at which anunintended pattern is unlikely to appear even if the corresponding pageof the passport 107 floats from the mounting surface 105 as a result ofdeformation or the like. Consequently, the second distance D2 is setlonger than the first distance D1. Hence, the white light source 131 ispositioned further from the page to be read 109 than infrared lightsource 121.

To avoid floating of the page as described above, conventional copiersand the like include a cover for holding the object to be read. However,the reading of the passport 107 is carried out, for example, for animmigration check at an airport and thus needs to be quickly finished.Thus, if each passport 107 is set and held using the cover, theoperation requires a long time. In contrast, as shown in FIG. 8, thereader device 101 according to the present embodiment need not include apresser cover and allows the passport 107 to be set on the mountingsurface 105 in a short time.

Now, with reference to FIG. 13, the arrangement of the white LED 135 f,located at the end of the white light source 131, will be described. Thearrangement of the white LED 135 f relates to the position of the code159 in the page to be read 109. The code 159 is provided close to andalong the long edge 153 of the page to be read 109, as described above.The end of the code 159 reaches the vicinity of the short edge 155 ofthe page to be read 109 and is positioned in the corner of the page tobe read 109.

The white LED 135 f is positioned at the further end of the white LEDarray 133. The position of the white LED 135 f corresponds to the code159 in the direction of the array. The white LED 135 f is arrangedhigher than the other white LEDs 135 a to 135 e in the white LED array133, that is, closer to the page to be read 109 in the perpendiculardirection. Specifically, the white LED 135 f is located at the sameheight as that of the infrared LED array 123. Such arrangement gives thefollowing advantages.

The passport 107 may be held in an owner's pocket for a long time andwet with the owner's sweat. The wetting and the subsequent drying or thelike or putting and taking the passport 107 into and out of the pocketsubjects the edges of the passport 107 to wave-like deformation(corrugation), with the end of each edge subjected to curleddeformation. In the pocket, the short edge 155 is positioned at thebottom portion of the pocket. Thus, the short edge 155 is likely toundergo such deformation.

When the wave-like deformation occurs, the angle between the page to beread 109 and the white light source 131 increases and decreasesperiodically along the short edge 155. In a place where the anglebetween the page to be read 109 and the white light source 131 is wider,the incident angle (=output angle) is narrower, thus allowing thespecular reflection condition to be locally established. Consequently,when the wave-like deformation occurs, the specular reflection conditionis periodically established along the short edge 155. As a result, asshown in the left half of FIG. 13, a plurality of small washed-out areasare created at intervals along the short edge 155. Depending on theshape of the corrugation, any of the washed-out areas overlaps the code159, the end of which lies in the washed-out area, as shown in FIG. 13.Thus, in an image generated using the white light source 131, the end ofthe code 159 is difficult to see. In particular, about one or twocharacters located at the end of the code 159 are difficult to see.

The code 159 is a target for automatic reading using the infrared lightsource 121. However, even in a visible light image picked up using thewhite light source 131, the entire code 159 needs to be displayed, forexample, to allow the result of reading to be checked. Thus, such awashed-out highlight phenomenon as described above needs to beprevented.

To accomplish this object, the present embodiment is configured suchthat the white LED 135 f, positioned so as to correspond to the code159, is locally arranged close to the page to be read 109. Thus, theincident angle (=output angle) of white light is wider at the positionof the code 159 than in the other places. Hence, even with a change inthe angle of the corner of the page to be read 109 resulting fromdeformation, the incident angle is prevented from decreasingexcessively. The specular reflection condition can thus be avoided. Thisserves to prevent possible washed-out highlight at the positioncorresponding to the code 159 as shown in the right half of FIG. 13.

When the white LED 135 f is arranged close to the page to be read 109,the irradiation range of the white LED 135 f is narrowed. This may causeilluminance unevenness. However, in the present embodiment, only thewhite LED 135 f is locally arranged at the different position. The otherwhite LEDs 135 a to 135 e irradiate the entire page to be read 9 withlight over a wide radiation angle. Hence, possible illuminanceunevenness is not significant enough to affect the check of the image.

Furthermore, as shown in FIG. 13, washed-out areas remain in a placewhere the code 159 is not provided. However, in the areas other than theone in which the code 59 is written, information with a high level ofimportance (for example, a photograph of the owner's face) is locatedclose to the center of the page so as to avoid the contamination ordeformation of the page. Thus, the present embodiment acquires a goodimage of the area of the code 159, which is likely to be deformed, whilesomewhat permitting the occurrence of washed-out highlight in areas inwhich information with a high level of importance is unlikely to bewritten.

Now, a modification of the present embodiment will be described. Theabove-described code 159 is an example of the near-edge code accordingto the present invention. In the present invention, the near-edge codeis positioned close to the edge of the object to be read. Morespecifically, the near-edge code is positioned close to the lightsource-side edge to allow the image for display to be obtained. At leasta part of the code is positioned close to the light source-side edge. Ifthe object to be read is a passport, the near-edge code is positionedclose to the end of the edge. Thus, the second light emitting element,lying at the furthest end, is located closer to the surface to be read(the second light emitting element emits the illumination light fordisplay). However, the position of the near-edge code and the like varydepending on the type of the object to be read. The arrangement of thelight sources may be correspondingly varied.

For example, the near-edge code may be positioned in the center of thelight source-side edge. In this case, the second light emitting elementcorresponding to the center of the edge is arranged closer to the objectto be read in accordance with the position of the near-edge code.

Furthermore, a plurality of second light emitting elements may bearranged closer to the object to be read for one near-edge code. Inother words, at least one second light emitting element is arrangedcloser to the object to be read without departing from the scope of thepresent invention. The number of second light emitting elements to bearranged closer to the surface to be read is suitably determineddepending on the interval between the elements and the width of thecode.

Additionally, the near-edge code need not be limited to a singleposition. A plurality of near-edge codes may be provided. In this case,a plurality of second light emitting elements may be arranged at aplurality of positions each of which is closer to the object to be read.

In addition, the plurality of near-edge codes may have differentpurposes, meanings, applications, levels of importance, and the like.Thus, the arrangement of the second light emitting element correspondingto the required near-edge code may be exclusively changed.

As described above, various modifications may be made without departingfrom the scope of the present embodiment. However, the passport 107 isoften put in the owner's pocket during flight and is likely to undergowave-like deformation. Moreover, the passport 107 contains the code 159reaching the corner of the page to be read 109. Significant deformationand thus washed-out highlight are likely to occur in the corner.Therefore, the present embodiment is significantly advantageous to thepassport 107.

The reader device 101 according to the present embodiment has beendescribed. In the present embodiment, the first light source is theinfrared light source 121. The first illumination light is infraredlight. The first wavelength band and the first radiation angle are thewavelength band and radiation angle of infrared light from the infraredlight source 121, respectively. Moreover, the first light emittingelement array and the first light emitting elements are the infrared LEDarray 123 and the infrared LEDs 125 a to 125 e, respectively.Furthermore, the second light source is the white light source 131,serving as an example of a visible light source. The second illuminationlight is the white light source. The second wavelength band and thesecond radiation angle are the wavelength band and radiation angle ofwhite light from the white light source 131 are respectively. Moreover,the second light emitting element array and the second light emittingelements are the white LED array 133 and the white LEDs 135 a to 135 f,respectively. Additionally, in the present embodiment, the object to beread is the passport 107, the surface to be read is the page to be read109, and the object placing unit is the mounting surface 105.

According to the present embodiment, the reader device 101 includes theinfrared light source 121 and the white light source 131. The whitelight source 131 has a wider wavelength band and a wider radiation anglethan the infrared light source 121. In the present embodiment, theinfrared light source 121 and the white light source 131 are arrangedoutside the front area of the surface to be read. The white light source131 is arranged further from the surface to be read than the infraredlight source 121 in the perpendicular direction. The infrared lightsource 121 is arranged closer to the surface to be read. Thus, even theinfrared light source 121 with a narrow radiation angle can irradiatethe required area on the surface to be read with light, ensuring thereading ability. Furthermore, the white light source 131 is arrangedfurther from the surface to be read than the infrared light source 121.This reduces the difference in the distance to the infrared light source121 which is dependent on the location of the surface to be read. As aresult, illumination unevenness is reduced, and the good image fordisplay is obtained. Moreover, for example, it is assumed that theobject to be read is covered with a laminate with an optical diffractionstructure and that the object to be read floats from the mountingsurface. Even in this case, since the white light source 131 is arrangedrelatively far from the surface to be read, the image for display can beprevented from containing an unintended pattern and the image can beprevented from being difficult to view. Thus, a reader device can beprovided which can properly illuminate the object to be read even whenplural types of light sources with different wavelength bands orradiation angles are used and which provides the good image even if theobject to be read floats.

Furthermore, according to the present embodiment, the surface to be readcontains the near-edge code. The near-edge code is positioned closer tothe second light source when the object to be read is placed on theobject placing unit. In the above-described embodiment, the near-edgecode is the code 159. The white light source 131 includes the white LEDarray 133 including the plurality of white LEDs 135 a to 135 f. Thewhite LED 135 f, included in the white LED array 133 and located at thenear-edge code position corresponding to the near-edge code, is arrangedcloser to the surface to be read than the other white LEDs 135 a to 135e in the perpendicular direction. Thus, in a place where the code 159 ispresent close to the edge of the surface to be read, the white lightsource 131 is locally arranged closer to the passport 107. Thus, even ifthe edge of the surface to be read is subjected to wave-like deformationas a result of wetting of the passport 107 or the like, a part of thecode 159 located close the edge can be prevented from being imaged underthe specular reflection condition. Therefore, illumination can beproperly provided so as to prevent the part of the code 159 located atthe edge from being difficult to see as a result of washed-outhighlight.

Furthermore, according to the present embodiment, the infrared lightsource 121 includes the infrared LED array 123 including the pluralityof infrared LEDs 125 a to 125 e. The white LED 135 f, located at thenear-edge code position, is arranged adjacent to the plurality ofinfrared LEDs 125 a to 125 e. In the above-described embodiment, thewhite LED 135 f is arranged adjacent to the infrared LED 125 e andoutside the infrared LED array 123. The white LED 135 f may be arrangedbetween two adjacent infrared LEDs. In this configuration, the whitelight source 131 can be suitably locally arranged closer to the objectto be read. Therefore, an image can be acquired in which possiblewashed-out highlight at the edge is prevented to allow the code 159 toappear properly.

Furthermore, according to the present embodiment, the code 159(near-edge code) is provided at the end of the edge of the surface to beread, that is, in the corner of the surface to be read. The white LED135 f, located at the near-edge code position, is positioned at the endof the white LED array 133 so as to correspond to the position of thecode 159. The corner is more seriously affected by deformation. However,according to the present invention, the white LED 135 f is locallylocated closer to the surface to be read, thus properly preventingpossible washed-out highlight in the corner.

Furthermore, according to the present embodiment, the first light sourceis the infrared light source 121, and the second light source is thewhite light source 131. In this configuration, the infrared light source121 is used to obtain the image for the reading process. The white lightsource 131 is used to obtain the image for display. The white lightsource 131 provides a wider wavelength band and a wider radiation anglethan the infrared light source 121. Even with such plural types of lightsources, the object to be read can be properly illuminated.Additionally, the good image is obtained even if the object to be readfloats.

Furthermore, in the reader device according to the present embodiment,the object to be read is the passport 107. In this configuration, evenif the object to be read is the passport 107 covered with a laminate orthe like, illumination with infrared light and white light can beproperly achieved. The good image is obtained even if the object to beread floats.

The currently possible preferred embodiments have been described.However, it should be appreciated that various modifications may be madeto the present embodiments. The accompanying claims are intended toembrace all such modifications falling within the spirit and scope ofthe present invention.

INDUSTRIAL APPLICABILITY

As described above, the reader device according to the present inventioncan provide the good image even if the page of the object to be read isdeformed as describe above. The reader device is useful as a documentreader device or the like, and particularly as a passport reader deviceor the like.

REFERENCE SIGNS LIST

-   1 Reader device-   5 Mounting surface-   7 Passport-   9 page to be read-   11 Mirror-   13 Camera-   21 Infrared light source-   23 Infrared LED array-   25 a to 25 e Infrared LEDs-   31 White light source-   33 White LED array-   35 a to 35 f White LEDs-   51 Binding edge-   53 Long edge-   55 Short edge-   59 Code-   101 Reader device-   105 Mounting surface-   107 Passport-   109 Page to be read-   111 Mirror-   113 Camera-   121 Infrared light source-   122 Infrared LED array-   125 a to 125 e Infrared LEDs-   131 White light source-   133 White LED array-   135 a to 135 f White LEDs-   151 Binding edge-   153 Long edge-   155 Short edge

1. A reader device comprising: an object placing unit on which an objectto be read with a surface to be read is placed; a light source whichilluminates the surface to be read placed on the object placing unit;and an imaging unit which picks up an image of the surface to be readilluminated by the light source, wherein the light source is arrangedoutside a front area of the surface to be read, the surface to be readincludes a near-edge code positioned close to an edge, and the lightsource includes a light emitting element array comprising a plurality oflight emitting elements, and a light emitting element included in thelight emitting element array and located at a near-edge code positioncorresponding to the near-edge code is arranged closer to the surface tobe read than the other light emitting elements in the light emittingelement array in a direction perpendicular to the object placing unit.2. The reader device according to claim 1, further comprising a mirrorwhich redirects an optical path between the surface to be read and theimaging unit, and wherein the light emitting element array is positionedsuch that main light from the light emitting elements is prevented fromtraveling to the surface to be read after reflection by the mirror. 3.The reader device according to claim 1, wherein the near-edge code isprovided at an end of the edge of the surface to be read, and the lightemitting element located at the near-edge code position is positioned atan end of the light emitting element array.
 4. The reader deviceaccording to claim 3, further comprising a mirror which redirects anoptical path between the surface to be read and the imaging unit, andwherein the mirror is inclined to the surface to be read, and the lightemitting element located at the near-edge code position is positioned atone of opposite ends of the light emitting element array which is closerto the mirror.
 5. The reader device according to claim 1, wherein thelight source includes: a first light source which irradiates the surfaceto be read with first illumination light with a first wavelength bandand a first radiation angle in order to acquire a first image used forreading processing, and a second light source which irradiates thesurface to be read with second illumination light with a secondwavelength band wider than the first wavelength band and a secondradiation angle wider than the first radiation angle in order to acquirea second image used for an application including display.
 6. The readerdevice according to claim 5, wherein the first light source is aninfrared light source, and the second light source is a visible lightsource.
 7. The reader device according to claim 1, wherein the object tobe read is a passport.